File Class
File Class
Description
A class for data manipulation of files in a file system.
Syntax
class File
Members
| Public Constructors | |
| File::File | Constructs a AmebaFatFS object. |
| Public Methods | |
| File::open | Open a file from the filesystem. |
| File::close | Close a previously opened file. |
| File::write | Write data to the currently open file. |
| File::read | Read data from the currently open file. |
| File::peek | Peek at the next data byte from the currently open file. |
| File::available | Check number of bytes remaining till end of file. |
| File::flush | Flush cached data. |
| File::seek | Move read write pointer. |
| File::position | Get current read write pointer. |
| File::size | Get file size. |
| File::isOpen | Check if a file is currently open. |
| File::name | Get currently open file name. |
File::File
Description
Constructs a File object.
Syntax
File::File(void);
File::File(const char* filename);
Parameters
filename: pointer to a char array containing the path of the file to open.
Returns
NA
Example Code
Example: CreateFolder
(https://github.com/ambiot/ambpro2_arduino/tree/dev/Arduino_package/hardware/libraries/FileSystem/examples/CreateFolder/CreateFolder.ino)
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::open
Description
Open a file from the file system.
Syntax
bool open(const char* filename);
Parameters
filename: pointer to a char array containing the path of the file to open.
Returns
This function returns true if the file is opened successfully, false otherwise.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::close
Description
Close a previously opened file.
Syntax
void close(void);
Parameters
NA
Returns
NA
Example Code
Example: CreateFolder
(https://github.com/ambiot/ambpro2_arduino/tree/dev/Arduino_package/hardware/libraries/FileSystem/examples/CreateFolder/CreateFolder.ino)
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function. Opened files need to be closed to ensure that any pending data is saved correctly.
File::write
Description
Write data to the currently open file.
Syntax
size_t write(uint8_t c);
size_t write(const uint8_t* buf, size_t size);
size_t write(const char* str;
size_t write(const char* buf, size_t size);
Parameters
c: single data byte to write
str: pointer to char array containing data to write, expressed as a null terminated string
buf: pointer to array containing data to write
size: number of bytes to write
Returns
This function returns the number of data bytes written to file.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::read
Description
Read data from the currently open file.
Syntax
int read(void);
int read(void* buf, size_t size);
Parameters
buf: pointer to buffer to store read data.
size: number of data bytes to read.
Returns
When a buffer pointer is not used, this function returns the data byte read if successful, otherwise it returns -1.
When a buffer pointer is used, this function returns the number of bytes read.
Example Code
Example: CreateFolder
(https://github.com/ambiot/ambpro2_arduino/tree/dev/Arduino_package/hardware/libraries/FileSystem/examples/CreateFolder/CreateFolder.ino)
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::peek
Description
Peek at the next data byte from the currently open file.
Syntax
int peek(void);
Parameters
NA
Returns
This function returns the next data byte if successful, otherwise it returns -1.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::available
Description
Check number of bytes remaining till end of file.
Syntax
int available(void);
Parameters
NA
Returns
This function returns the number of bytes available to read until the end of file.
Example Code
Example: ReadHTMLFile
(https://github.com/ambiot/ambpro2_arduino/tree/dev/Arduino_package/hardware/libraries/FileSystem/examples/ReadHTMLFile/ReadHTMLFile.ino)
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::flush
Description
Flush cached data.
Syntax
void flush(void);
Parameters
NA
Returns
This function flushes any cached data and writes all pending data into file.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::seek
Description
Move the file read/write pointer of the currently open file.
Syntax
bool seek(uint32_t pos);
Parameters
pos: file position to move to
Returns
This function returns true if the file pointer is move successfully, false otherwise.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function. If the target position is larger than the size of the currently open file, the file size will be increased as required.
File::position
Description
Get the read/write pointer of the currently open file.
Syntax
uint32_t position(void);
Parameters
NA
Returns
This function returns the current file read/write position.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::size
Description
Get the size of the currently open file.
Syntax
uint32_t size(void);
Parameters
NA
Returns
This function returns the size of the currently open file.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::isOpen
Description
Check if a file is currently open.
Syntax
NA
Parameters
This function returns true if a file is currently open, false otherwise.
Returns
This function returns true if the path points to a folder, false otherwise.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
File::name
Description
Get the filename of the currently open file.
Syntax
const char* name(void);
Parameters
NA
Returns
This function returns a pointer to a character array containing the filename of the currently open file. If no file is open, it returns NULL.
Example Code
NA
Notes and Warnings
“AmebaFatFSFile.h” must be included to use the class function.
